<!doctype html>
<html>
 <head>
 <meta charset="utf-8">
 <title>Rotational Velocity</title>
 <link rel="stylesheet" href="style.css">
 </head>
  <body>
 <canvas id="canvas" width="400" height="400"></canvas>
 <script src="utils.js"></script>
 <script src="arrow.js"></script>
 <script>
 window.onload = function () {
 var canvas = document.getElementById('canvas'),
 context = canvas.getContext('2d'),
 mouse = utils.captureMouse(canvas),
 arrow = new Arrow(),
 vr = 2; //degrees
 arrow.x = canvas.width / 2;
 arrow.y = canvas.height / 2;
 (function drawFrame () {
 window.requestAnimationFrame(drawFrame, canvas);
 context.clearRect(0, 0, canvas.width, canvas.height);
 arrow.rotation += vr * Math.PI / 180; //to radians
 arrow.draw(context);
 }());
 };
 </script>
 </body>
</html>